Carol Major

What do you think are the potential benefits and/or drawbacks of home-based testing in Canada?

Any test that will increase the numbers of at-risk people knowing their HIV status should be of net benefit. The OraQuick oral fluid test is easy to do, non-invasive (i.e., it doesn't require a finger stick or needles), and is readily accepted. On the surface, it sounds great. However, there are a number of drawbacks that must be taken into account.

The relatively poor sensitivity is my first concern. The HIV home-based testing article points out that up to 10% of people with HIV infection will test negative using the OraQuick test. What it doesn't explicitly state is that those who are in the "window period" and most likely to have a false negative, have early HIV infection, when their viral load is highest and they are most infectious. So, if the test is being used by those at risk to assess whether or not they should use protection, and they happen to be in the "window period" there is the potential for some very disastrous outcomes.

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My background is HIV laboratory testing and I have experience with all the detailed technical issues that need attention to guarantee the reliability and accuracy of results. I should point out that the window period for oral fluid is from several days to weeks longer than it is for a blood test. Most standard lab blood tests now detect both antigen and antibody. The licensed HIV point-of-care (POC) test in Canada (bioLytical INSTI™ HIV), detects antibodies in a drop of blood, up to several weeks earlier than the oral fluid test will detect antibodies. AND, if a person testing through an Ontario HIV POC testing site is in the window period and has a negative POC test, a standard blood test will be recommended and done through the program (in order to look for p24 antigen).

My second concern is the lack of what lab folks call "Quality Assurance." All lab tests must be monitored to ensure they are performing properly. Once these kits are released onto the market, there is no provision to ensure they are performing as expected. Products can be affected by storage conditions, user variation, or could be subject to early deterioration due to contamination or subtle variations in any of the reagents in the product. Even though the Ontario POC testing program is not lab-based, it ensures kit performance with controls run at regular intervals, participation in an external quality assessment program (that is, blind samples sent to sites by a lab quality assurance agency, that must be tested and results sent back for assessment) and regular lab-based testing of a proportion of clients tested by the POC test. With all of these processes (and more), we are able to ensure consistent specificity and sensitivity (performance) of the INSTI test -- the test used at Ontario's POC sites.

The issue of counselling, support and referral is paramount. How can we ensure appropriate follow-up for those who are reactive (indicating a potential positive result), and those who are negative but potentially in the window period? Although the specificity of the oral fluid test is good, there will still be false reactive results. It is imperative that people with reactive home tests have a standard lab test to confirm the result.

Another concern I have is that home-based testing opens the door to coercive testing (i.e., partners testing partners, pre-employment, school admission, etc.). We have worked hard to ensure that HIV testing is voluntary and if desired, anonymous. Putting this test into an uncontrolled market place, puts that in question.

I don't really think the Home Access type of test where the client has to prepare a dried blood spot from a finger stick is really in the running. It has not done well in the U.S. and is not an attractive alternative for people who wish to have an HIV test. It is invasive and you have to wait up to two weeks to get the results. On the other hand, as the test is actually done in a lab, many of the quality issues are not of concern. Collecting a dried blood spot for oneself is not easy though, and many users may not get a result as the sample they collected and sent in will be inadequate.

Do you think home-based testing has a role to play in Canada? Please tell us why.

Clearly, I have some very serious reservations about the use of an oral fluid home test in Canada. Having said that, we still have a significant number of people living with HIV infection who have not been diagnosed, and whatever would facilitate those people learning about their HIV infection would be welcome.

We will need to be strategic in the use of these tests, so that they could facilitate those least likely to come forward for any type of professional service to be tested. Perhaps they would be useful under some type of supervision in outreach settings with vulnerable populations? Where people could do the test themselves, but have support close by to ensure appropriate counselling and follow-up.

The kits are, however, very expensive and so there would need to be a compelling cost benefit to use these tests in addition to the currently licensed POC tests.

Making this test available over the counter, is likely to increase testing for affluent, worried well and potentially some people who may have been or are at risk for HIV, but are unwilling to approach a care provider for fear of disclosing personal details. That could be a good thing, but again the concern is how to ensure the continuity of care for those who do test reactive? As we expand our focus on access to care, treatment adherence and viral suppression, otherwise referred to as the "treatment cascade," there is the need for more interaction with the healthcare system, at least initially after testing positive, not less. The concern with self-testing is that these opportunities to engage HIV-positive individuals with the healthcare system may be delayed or lost. And, of course, we would need to address the issue of ensuring the ongoing quality of the results.

Do you think self-testing has a role to play in settings such as emergency rooms or community-based agencies?

The bioLytical INSTI HIV test is licensed in Canada for POC HIV testing. Its sensitivity and specificity are better than the OraQuick kit, so there is no advantage for emergency rooms to move to a more expensive product with poorer performance.

Community-based agencies can also use the current POC test as long as there are trained staff available to provide the service. There might be an additional role for an innovative outreach program with a self-test to encourage vulnerable populations to learn about their HIV status. We would need to ensure that appropriate counselling, support and referral was in place in these settings, in order to ensure the continuum of care.

What are the conversations that would need to happen in Canada to prepare us for the possibility of home-based testing? Who should be part of that conversation?

Canada needs to establish its own acceptable performance specifications (sensitivity, specificity). We need to consider whether we are prepared to give up sensitivity for wider test coverage; as well as the potential fall-out from the sensitivity issues and increased HIV transmission versus the increased diagnosis of those who were unaware of their HIV infection

We need to determine if the test needs any safeguards (i.e., distributed by specific professionals -- medical, social, etc.) or some type of quality assurance to ensure kit performance over time.

We need to consider follow-up if the test is made widely available and outside a structured counselling setting/healthcare interaction. How can we support those who test positive and ensure they receive appropriate counselling and referral?

We need to consider the financial costs. Is it all user pay, or is there some benefit to using these in a prevention program setting?

Parties with an interest in this discussion would include: federal and provincial laboratory experts, Health Canada Therapeutic Products Regulators, HIV community leaders and legal experts, community agencies, healthcare funders, provincial HIV organizations and social justice groups.

This is a complicated issue. We want people living with HIV to learn about their infection so they can get care and reduce further transmission. Any advance in technology that would assist us with that is welcome. But, we do need to ensure that the new technology will be a net benefit and not ultimately cause more problems than it solves.

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